Conventionally, monitoring of a monitoring object apparatus which uses an analog meter as a measuring instrument is performed by a customer engineer periodically visiting the relevant site and checking a measured value of the analog meter by visual observation. It is desirable that such work to check the measured value of the analog meter should be conducted with high frequency; however, this results in problems of cost escalation and a labor shortage due to aging of customer engineers.
As one method for solving such problems, there has been conventionally suggested a method of causing a fixed point camera to photograph an analog meter which is a monitoring object apparatus, thereby reading measured values of the analog meter by executing image analysis processing on captured images, and transferring the read result as data to, for example, a monitoring center (see, for example, PTL 1). Such a monitoring method has the advantage of being capable of monitoring a status of the monitoring object apparatus with good accuracy without increasing the costs or using manpower.